Using autoresponder without internet

I use Fiddler to redirect the browser to local resources to test my library components before I push them up to github.  This works really great using localhost while working in webstorm.  

If I want to work without internet though (e.g. on a plane), the redirect fails.  I get net::ERR_TUNNEL_CONNECTION_FAILED errors in the browser for resources that I would normally redirect to local versions.  

 I thought that Fiddler would intercept these requests and just respond with the local resource, but the browser is trying to GET from the remote resource.  

Why is this and how can I fix it?